diff_sim_failure_results

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the behavioral disclosure burden. It discloses the comparison's output dimensions and the important dependency on parse_sim_log snapshot timing. It does not explicitly state read-only/no side effects, but the described behavior is otherwise transparent for a comparison utility.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, front-loaded with the core purpose and return categories, followed by a compact caveat. There is no filler, no repetition of schema field names, and every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no output schema and no annotations, the description covers the returned information, parameter selection, and a critical workflow edge case. The only notable gap is not telling an agent when to choose this over diff_first_divergence, and not describing the exact output format.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description adds value beyond the schema by explaining the workflow relationship between new_log_path and parse_sim_log snapshots, and clarifying when snapshot IDs can substitute for paths. This is meaningful parameter semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Compare normalized failure events from two simulation logs.' It then enumerates what is returned (resolved, persistent, newly introduced failures, changes in failure type, X/Z presence, first-failure timing, convergence summary), which clearly differentiates it from siblings like parse_sim_log and diff_first_divergence.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides concrete procedural guidance for the tricky same-path overwrite case: pass new_log_path only after parse_sim_log has captured the baseline snapshot, or pass snapshot IDs. It does not explicitly name alternatives or state when not to use this tool, so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.